Steady-State and Dynamic Properties of the Floating-Ring Journal Bearing

Abstract

Calculated data on steady-state and dynamic properties of the plain cylindrical floating-ring bearing with pressurized lubricant supply are given. The data are for a bearing with L/D of 1, and values of the ratio of inner to outer film clearances of 0.7 and 1.3. One value of dimensionless supply pressure parameter is covered. Experimental results are presented which verify the calculated results and which supplement them, particularly with respect to stability characteristics of the bearing.

Discussion: “Angular-Compliant Hydrodynamic Bearing Performance Under Dynamic Loads” (Harnoy, A., and Rachoor, H., 1993, ASME J. Tribol., 115, pp. 342–347)

“…To lubricate the sleeve the oil is fed in the axial direction. Ng (1965 and1968), Tanaka andHory (1972), Nikolajsen (1973), and Rhode and Ezzat (1980) also contributed to the idea of splitting the total shaft speed between two bearings was also developed by using two hydrodynamic bearings in series (floating ring or bush bearing). The desired ratio between bearing speeds can be established, for instance, by choosing the corresponding ratio between bearing clearances.…”

Angular-Compliant Hydrodynamic Bearing Performance Under Dynamic Loads

“…To lubricate the sleeve the oil is fed in the axial direction. Ng (1965 and1968), Tanaka andHory (1972), Nikolajsen (1973), and Rhode and Ezzat (1980) also contributed to the idea of splitting the total shaft speed between two bearings was also developed by using two hydrodynamic bearings in series (floating ring or bush bearing). The desired ratio between bearing speeds can be established, for instance, by choosing the corresponding ratio between bearing clearances.…”

Stability Effects of Non-Circular Geometry in Floating Ring Bearings

“…Oil whirl and whip, bifurcations from one limit-cycle to a different one, with collapse of the limit-cycle itself or the possible evolution to a severe, total instability, are the ingredients of the dynamics of FRBs supported rotors [1,2]. The above remarks justify a bulk investigation carried out in decades, especially focused on the effects of the different parameters on the static and dynamic properties of the FRB [3][4][5][6][7][8], largely motivated by the need to guarantee higher specific power with lightweight assemblies and to overcome as far as possible the major drawbacks of non-linear instabilities. Shaw and Nussdorfer [3] mentioned the early use of such bearings in the connecting rods of the 1920-1930 Bristol aircraft engines.…”

“…An experimental measurement of the whirl to rotating speed ratio of the ring was also carried out in their study. Ng and Orcutt [4] calculated the stiffness and damping coefficients of the FRB around the static equilibrium position through linearization of the film forces. Fractional-frequency whirling was observed in the experimental tests, whereas the whirl amplitude was controlled through the oil feeding pressure, the oil viscosity, and the outer clearance.…”